I bought a 2GB Apacer Handi-Steno HT-203 (supposedly the fastest) USB stick for my 2GB RAM Vista Ultimate PC w/2 WD 10K RPM Raptor HDDs and try as hard as I could , so as to justify the time and expense, I didn't notice an improvement in speed. I did see that the LED on the USB stick was flickering most all the time, lots of activity, but no sense of immediate refreshing of anything I had been working on.
I now use the Apacer for an emergency backup our web sites so I'm OK with the purchase.
It configures itself when you plug it in with a simple, "YES use for Ready Boost," and it can easily be reconfigured to use as a regular USB HDD.
from what I gather, The ready boost can help you alot if you would normally depend on paging files...(meaning you don't have much ram)
*(paging file is an area on the Hard Disk that Windows uses as if it is RAM)
*The hard drive is much slower to read from than a high speed flash drive
so say your comp has only 512 MB Ram; using ready boost would be much faster than using paging files on the hard drive to edit movies or whatever other high resource programs you run.
I have noticed that it seems to slow my comp down if I try using ready boost because 2 GB of ram takes care of most every day tasks and I don't usually need to use page files.